(i) Field of the Invention
The present invention relates to a method for separating off coloring components from aqueous plant extracts and also to the use of magnesium salts for separating off coloring components from aqueous plant extracts.
(ii) Description of the Related Art
In the isolation of valuable constituents from plants, routinely aqueous extraction is used. In this case, generally, plant material is comminuted and extracted with warm water with stirring. The extracts thus produced are frequently colored deep brownish-yellow owing to their content of tannins and flavonoids, for which reason the constituents directly isolatable from such extracts in no way correspond to the desired requirements with respect to a neutral color.
The above-described problem occurs, for example, in the isolation of inulin from artichokes. Decolorization attempts following the decolorization method employed in the isolation of sucrose from sugarbeets for extracts from beets by addition of chalk and subsequent carbonation (CO2 addition) do not proceed satisfactorily. Equally, the possible use of ion exchange resins for decolorizing the extracts is excluded owing to the high cost required therefor.